Dampening unit of a planographic printing machine

Abstract

A dampening unit of a planographic printing machine has a pan roller, a transfer roller, and a dampening unit roller. The transfer roller is held in bearing contact against the dampening unit roller with a regulating force such as, in particular, a spring force F F . The transfer roller, together with the pan roller, is pivotable about a pivot axis that is offset relative to the roller axis of the pan roller, and/or the pivot axis lies essentially on a tangential line running through a circumferential contact point which is formed by the transfer roller together with the dampening unit roller.

I claim:  
     
       1. A dampening unit of a planographic printing machine, comprising: 
       a first roller rotatably mounted about a first roller axis;  
       a second roller rotatably mounted about a second roller axis;  
       a third roller rotatably mounted about a third roller axis;  
       said second roller and said third roller being ink-friendly, emulsion-carrying rollers;  
       a roller drive driving said third roller with a rolling slip relative to said second roller;  
       a common roller carrier having a pivot axis and commonly supporting said first roller and said third roller such that said first roller and said third roller are pivotably disposed about said pivot axis, said pivot axis being offset from said first roller axis, said second roller axis, and said third roller axis;  
       a spring coupled to said common roller carrier; and  
       said third roller disposed to be held, by said spring generating a regulating force and with said common roller carrier, in bearing contact against said second roller at a circumferential contact point.  
     
     
       2. The dampening unit according to  claim 1 , wherein said first roller is an ink-friendly, emulsion-carrying roller. 
     
     
       3. The dampening unit according to  claim 1 , which comprises a rotary bearing defining said pivot axis, said rotary bearing being rotatable in a first direction in which said third roller is thrown onto said second roller and being rotatable in a second direction in which said third roller is thrown off from said second roller. 
     
     
       4. The dampening unit according to  claim 3 , wherein said rotary bearing having said pivot axis includes a rotatable freewheel coupling slidably mounted, so as to be rotatable, in a pivot joint bore formed in a machine frame, and a joint pin inserted and non-rotatably fixed in said freewheel coupling. 
     
     
       5. The dampening unit according to  claim 3 , wherein said rotary bearing having said pivot axis includes a rotatable freewheel coupling slidably mounted, so as to be rotatable, on a joint pin, and non-rotatably fixed in a pivot joint bore of a machine frame. 
     
     
       6. The dampening unit according to  claim 1 , wherein said common roller carrier commonly supports said third roller and said first roller, and said common roller carrier includes a setting device for setting an adjustable roller center spacing distance between said first and third roller axes. 
     
     
       7. The dampening unit according to  claim 6 , wherein said setting device for setting the adjustable roller center spacing distance on said common roller carrier displaces said first roller relative to said third roller. 
     
     
       8. In combination with a planographic printing machine, at least one dampening unit according to claims  1 . 
     
     
       9. The dampening unit according to  claim 1 , wherein said rotary bearing includes: 
       a joint pin and a freewheel coupling, said freewheel coupling including an inner ring and an outer ring;  
       said inner ring being non-rotatably fixed on said joint pin;  
       an element selected from the group consisting of a pivot joint bore and a bush inserted in a pivot joint bore, said outer ring being slidably mounted on said element so as to be rotatable in said second direction; and  
       said freewheel coupling being rotatable with respect to said rings in said first direction.  
     
     
       10. The dampening unit according to  claim 1 , wherein said rotary bearing includes: 
       a pivot joint bore and a freewheel coupling;  
       said freewheel coupling including an inner ring and an outer ring;  
       an element selected from the group consisting of a joint pin and a bush on a joint pin, said inner ring being slidably mounted on said element so as to be rotatable in said second direction;  
       said outer ring being non-rotatably fixed in said pivot joint bore; and  
       said freewheel coupling being rotatable with respect to said rings in said first direction.  
     
     
       11. The dampening unit according to  claim 1 , which comprises a rotary bearing defining said pivot axis, said rotary bearing being rotatable in a first direction in which said third roller is pressed against said second roller, and being rotatable in a second direction in which said third roller is moved away from said second roller.